Integrated immunoreactivity analysis of MHC-I epitopes derived from the Marburg virus glycoprotein.

INTRODUCTION

Marburg virus (MARV) is a hemorrhagic fever virus, and its glycoprotein (GP) represents an important target for vaccine research. MHC class I (MHC-I)-restricted T cell epitopes are critical for inducing cytotoxic CD8+ T cell responses. In this study, we aimed to identify MHC-I-restricted T cell epitopes derived from the MARV Angola strain GP through an integrated bioinformatics and experimental approach.

METHODS

We retrieved the MARV Angola strain GP sequence and divided it into 673 overlapping 9-mer peptides. By integrating five computational prediction algorithms, immunogenicity scoring tools and BLASTp conservation analysis, we screened 9-mer peptides from the MARV Angola GP. Molecular docking was performed with MHC-I structures using HPEPDOCK and molecular dynamics (MD) analysis. Bidirectional hierarchical clustering was used to analyze binding similarity across MHC-I molecules. Mutations identified in epitope regions were tested for their effect on affinity. Toxicity and allergenicity of the epitopes were predicted using dedicated tools. Finally, BALB/c and C57BL/6 mice were immunized with a DNA vaccine encoding MARV GP. IFN-γ secretion in mouse splenocytes was then measured by ELISpot, serum IgG by ELISA, and CD8+ T cell cytokine production by flow cytometry.

RESULTS

Among 673 GP peptides, eight epitopes (GAFFLYDRI, REGDMFPFL, DMFPFLDGL, NENDCDAEL, AGLSWIPFF, NQNNLVCRL, TGWGLGGKW, SDWGVLTNL) were predicted to exhibit high-affinity MHC-I binding, strong immunogenicity, and intraspecies conservation. Bidirectional hierarchical clustering analysis, molecular docking, sequence alignment, and toxicity/allergenicity predictions suggested binding across selected alleles, structural stability, limited impact from identified mutations, and low predicted toxicity. In subsequent ELISpot validation, eight epitopes elicited strong IFN-γ responses. In addition, serum from GP-immunized mice contained IgG that bound the corresponding linear peptide sequences.

CONCLUSION

An integrated computational-experimental pipeline identified eight conserved, immunogenic MHC-I epitopes from MARV GP. These selected epitopes may serve as promising candidates for future vaccine design.